Prior to producing this invention, the inventor proposed two different types of stage systems, namely a high-type one and a low-type one in Japanese Application for Registration of Utility Model No. 59-100829 (published under No. 61-16200). Either of the high-type and low-type stage systems has a guide post to be fixed to a wall or the like, and a balancer mechanism supporting the rear portion of the stage body for vertical movement. Also, either type of system has, on its front portion, wheels to enable the stage body to be moved on a floor. The stage body of either type of system can be displaced or stored from a horizontal position on the floor to a vertical position adjacent to the post. The high-type system includes legs pivotally connected to the bottom of a platform so that the legs make right angles with the platform when supporting the platform on the floor, but change their angles to the platform as the legs are raised away from the floor when the stage body is removed to the vertical position, and become parallel to the platform when the platform is removed to a vertical position. On the other hand, the low-type system includes legs fixed to the bottom of a platform.
However, either type of system may be used only in a place inside or outside a building where its guide post can be fixed to a wall or the like. Also, the stage body cannot have a depth greater than the height of the post. In other words, the depth of the stage body is limited by the height of the post. Therefore, if either type of system is manufactured for use in a place with a floor-to-ceiling height of only 3 to 4 meters, such as a schoolroom, a recreation room or an assembly room of a school or a kindergarten or in an assembly room, a council room or a grand hall of a hotel or the like, the system cannot have a stage body having a depth of more than 3 to 4 meters. Thus it may further be said that the depth of the stage body is limited by the height from the floor to the ceiling.
A stage system similar to the foregoing ones was also proposed in Japanese Application for Registration of Utility Model No. 52-82315 (published under No. 60-25482) filed in the name of the inventor hereof.
Also, a folding stage system was proposed in Japanese Patent Application No. 41-44861 (published under No. 45-30907 and corresponding to U. S. Patent application Ser. No. 509138 filed Nov. 22, 1965). This stage system includes a pair of stage components connected to each other so that the components can be displaced from horizontal positions to opposed vertical positions. Thus, if the stage system is used in a room having a floor-to-ceiling height slightly greater than the "folded height" of the system, the system may be so unfolded as to have a depth much greater than the floor-to-ceiling height. That is, the depth of the system is not limited by the floor-to-ceiling height. Also, if a plurality of such stage systems are arranged on a floor in such a manner that the systems make contact with one another, a stage with a desired area may be obtained.
However, the foregoing stage system of the Application No. 41-44861 must be manually folded or unfolded. In other words, its two stage components must be manually displaced from their horizontal positions to their vertical positions or vice versa. Therefore, the stage components each must be one having such a weight or size that the user or operator can manually displace the component. Also, if a plurality of the stage systems are to be arranged on a floor to provide a stage with a desired area, each system must be manually carried or moved to the required position. Also, since the two stage components of the system are displaced with distal side portions of the components upwardly arcing, additional stage systems cannot be connected to the distal side portions of the system components to provide a larger stage system.
In order to solve the foregoing problems of the prior art the inventor hereof proposed novel electrically-operated stage systems in Japanese Patent Applications Nos. 63-9407 and 63-72712, now U.S. Pat. No. 4,872,295 issued Oct. 10, 1989.